Air conveyor deck

ABSTRACT

An air lift conveyor is provided with adjustable air flow defining nozzles that may be located in the bottom of the conveyor channel, in the side walls or in the top as may be desired according to the effect to be achieved. The air flow directing nozzles are formed by cooperating tongues, on each of two parallelly adjacent members, each of which extends into a slot in the adjacent member. The members are slidable relative to each other to adjust the spacing between the tongues and thus the flow characteristics of the nozzles.

Johnston [1 11 3,759,579 [4 1 Sept. 18,1973

AIR CONVEYOR DECK [75] Inventor: William F. Johnston, Louisville, Ky. Ian-{nary Exami'fer Richard Aegerter Assistant ExammerW. Scott Carson [73] Assignee: Rex Chainbelt Inc Milwaukee, Wis. Attorney-Marshall & Yeasting [22] Filed: Nov. 26, 1971 I 21 Appl. N0.: 202,406 [57] ABSTRACT An air lift conveyor is provided with adjustable air flow defining nozzles that may be located in the bottom of [22] US. Cl. 302/31 the conveyor channel, in the side walls in the top as ll!!- Cl. BfiSg 51/02 y be desired according to the effect to be achieved FIG! 0 Search 302/2 R, 29, 31 The air flow directing nozzles are formed y cooperab ing tongues, on each of two parallelly adjacent mem- [56] References Cited bers, each of which extends into a slot in the adjacent UNITED STATES PATENTS member. The members are slidable relative to each 2,882,097 4/1959 Hamren 302/29. other to adjust the spacing between the tongues and 3,475,058 l0/l969 Sanders..... 302/29 thus the flow characteristics of the nozzles. 3,180,688 4/1965 Futer 302/29 3,647,266 3/1912 l-lurd er al 302/31 5 Chums, 7 Drawing Figures 24 4 v n: f

| 5 J l I l PAIENTEnsm ems 3159.579

l 7 v T 7" Fif' BACKGROUND OF THE INVENTION wall of the conveyor and entering the conveyor channel in a downstream direction. Another popular form resembles a series of louvers providing laterally extending slots through which the air passes with a substantial downstream velocity to not only support the material but also to propel it along the conveyor channel.

SUMMARY OF THE INVENTION According to the invention a portion of the conveyor channel, which may be the bottom or deck of the channel, a side wall, or the top, is constructed of parallel, closely adjacent plates each of which is transversely slotted with a depressed tongueextending along one side of each slot. Each tongue is adapted to enter a corresponding slot of the other plate. member and overlap the tongue along that slot to form the sides of an air jet nozzle. The spacing between and overlap of the tongues is adjusted by moving the plates relative to each other. The nozzles are preferably directed in a downstream direction to direct flat sheets of air in a downstream direction between the deck or wall of the conveyor channel and the material in the channel.

While the nozzles are usually located in the bottom of the conveyor channelso that the air jets support the material, the nozzles are located inside walls particularly on curves in the channel or at the entrance side of switches where the material is to be directed to one of two or more diverging channels.

In each case, means are provided to maintain a pressure difference across the wall or deck containing the nozzles to maintain the air flow through the nozzles. Usually, the means comprises a plenum chamber extending along the deck or wall, the plenum chamber being supplied with air from a blower or fan. Altematively, the channel can be closed and air exhausted from its downstream end to produce the air flow through the nozzles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view, at small scale, of the improved of a modified form of deck for the conveyor.

FIG. 7 is a plan view at enlarged scale, of a fragment of conveyor deck showing another modification thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 of the drawings, the improved conveyor comprises a trough 1 that is divided into an upper section or channel 2 and a plenum chamber 3 by a deck 4. A fan 5 that is driven by a motor 6 supplies air under pressure through a conduit or air pipe 7 into the plenum chamber 3.

The deck 4, as may beseen in greater detail in FIG. 3, comprises an upper plate 10 and a lower plate ll, the lower plate being supported by any suitable means such as angle irons 12 extending along the sidewalls of the trough 1.

The upper plate 10, at regular intervals, is slotted transversely to provide openings 13 extending laterally nearly the full width of the trough l. The longitudinally extending sides of the openings 13 are extended in a downstream direction of the conveyor as slits and the material therebetween is bent downwardly to form a series of downwardly directed tongues 14. In like manner, the lower plate 11 is also transversely slotted to provide openings 16. The material upstream to the left in FIGS. 3 and 5, adjacent each of the openings 16 of the lower plate 1 1 is bent upwardly to form tongues 17. The spacing of the openings 16 in the lower plate 1 1 is the same as the spacing of the openings 13 in the upper plate 10.

The two plates 10 and 11 are assembled with the tongues 14 of the upper plate extending downwardly through the slots 16 of the lower plate 11 and with the tongues 17 of the lower plate extending upwardly into the slots 13 of the upper plate 10. The flat adjacent portions of the plates 10 and 11 are substantially in contact in the assembled form and the lower surface of the tongues 17 of the lower plate overlap the upper surfaces of the tongues 14 of'the upper plate to form nozzles through which air enters the conveyor channel.

In operation, air from the plenum chamber 3 flows in a downstream direction along the surface of the lower plate 11, follows upwardly along the lower surface of a tongue 17 and through nozzles 20 formed between the overlapped portions of the tongues 17 and 14 and exits into the upper section 2 of the conveyor along the supper surface of a downwardly depressed tongue 14 of the upper plate 10. 1 I

The lower plate 11 is longitudinally adjustable with respect to the upper plate 10 thus permitting the vertical dimension of orifices or nozzles 20 between the tongues 14 and 17 to be varied and thus control the velocity of the air flow, as indicated by the arrows 21, and

the restriction of the gaps or orifices 20 to be adjusted in accordance with the requirements of the particular material being conveyed in the conveyor.

Any suitable mechanism may be used to adjust the relative positions of the lower plate 11 with respect to the upper plate 10. This may include, for example, a small hand wheel 24 on a shaft extending longitudinally from the end of the conveyor trough 1. The shaft may be threaded and engage a nut attached to the lower surface of an adjacent portion of the lower plate 11.

' In some cases, it is desirable that the air issuing from the plenum chamber into the upper section 2 of the trough be divided as a series of laterally adjacent jets instead of the single flat sheet of air as would issue through the gaps or nozzles 20 between the tongues 14 and 17. Such an arrangement of the air flow may be obtained by providing the downstream edge of tongues 17a of the lower plate with a series of slots 26 (FIG. 6) extending from such downstream edge a suitable distance toward the upstream portion of the tongue. The lengths of the slots may be such that the slotted portion of the tongue 17a overlaps the upstream edge of the tongue 14a of an upper plate 10a. This arrangement of slots has the efl'ect of allowing some of the air to issue in a more nearly vertical direction from the plenum chamber into the upper section of the trough. This provides greater lifting effort without detracting substantially from the forward drive exerted by the air flowing through the nozzles 20 and acting on the material in the trough.

In the event more lifting force is required holes 28 and 29 (FIG. 7) may be drilled in the upper and lower plates 10b and 11b respectively in the areas generally midway between the nozzles 20. Air flow from the plenum chamber through the holes provides a vertical lifting force to keep the material in the conveyor free from the deck 4.

The combination of the two plates with the interengaging tongues that are adjustable relative to each other provides the capability of so controlling the air flow that practically any conveyable material may be efficiently conveyed, either from a standing start, i.e. conveyor channel filled with the product before starting the air flow, or in the usual mode of supply air from the plenum chamber before supplying material to the conveyor.

I claim:

1. In an apparatus in which material is moved by air jets, in combination, a conveyor channel, a portion of said channel adapted to face and extend along the path of the material to be moved, means for maintaining a pressure difierential across said portion, said portion comprising a pair of plates each of which has a plurality of slots bounded along one side by a tongue the surface of which is inclined to the plane of the portion, each slot being separated from the next adjacent slot by a flat portion of said plate, the tongues of each plate being inserted into adjacent slots of the other plate with said flat portions juxtaposed and said tongues cooperating to from air jet nozzles for directing air flowing through the portion along a path inclined to the portion, said plates being adjustable relative to each other to vary the spacing between said inclined surfaces of the tongues and thus the flow characteristics of the nozzles.

2. In an apparatus according to claim 1, a plenum chamber extending along said portion in communication with said slots, and means for supplying gas under pressure to said chamber.

3. In an apparatus according to claim 1, adjusting means interconnecting said plates for moving one plate relative to the other along a line generally normal to the length of the slots.

4. An apparatus according to claim 1, in which at least some of the tongues are slotted with the slots extending generally parallel to the direction of conveying of the material being conveyed.

5. An apparatus according to claim 1, in which at least one of said plates in the region between the slots is perforated. 

1. In an apparatus in which material is moved by air jets, in combination, a conveyor channel, a portion of said channel adapted to face and extend along the path of the material to be moved, means for maintaining a pressure differential across said portion, said portion comprising a pair of plates each of which has a plurality of slots bounded along one side by a tongue the surface of which is inclined to the plane of the portion, each slot being separated from the next adjacent slot by a flat portion of said plate, the tongues of each plate being inserted into adjacent slots of the other plate with said flat portions juxtaposed and said tongues cooperating to from air jet nozzles for directing air flowing through the portion along a path inclined to the portion, said plates being adjustable relative to each other to vary the spacing between said inclined surfaces of the tongues and thus the flow characteristics of the nozzles.
 2. In an apparatus according to claim 1, a plenum chamber extending along said portion in communication with said slots, and means for supplying gas under pressure to said chamber.
 3. In an apparatus according to claim 1, adjusting means interconnecting said plates for moving one plate relative to the other along a line generally normal to the length of the slots.
 4. An apparatus according to claim 1, in which at least some of the tongues are slotted with the slots extending generally parallel to the direction of conveying of the material being conveyed.
 5. An apparatus according to claim 1, in which at least one of said plates in the region between the slots is perforated. 